1. Field of the Invention
The invention involves a structural panel for use as a modular wall unit in a building, and more particularly, a structural panel which incorporates a novel structural interlocking joint system.
2. Description of the Prior Art
A typical structural panel, such as a prefabricated building panel, may be used in place of conventional framing at the job site. These prefabricated building panels are manufactured at an off-site manufacturing facility. The panels are then transported to the job site, where they are assembled to construct a building.
Some building panels are constructed as a sandwich-type panel by gluing a skin on each side of a core consisting of urethane foam, verathane foam, styrofoam, and the like. In U.S. Pat. No. 3,462,897 to G.H. Weinrott, issued Aug. 26, 1969, urethane foam was used for the core. This type of core provides very good insulation, but also poses a problem being a fire hazard and emitting toxic fumes when burning. A sandwich-type panel usually requires additional structural members to complete a building.
Certain structural panels have design configurations which create difficulties in manufacturing or which dictate the method and speed by which panels can be manufactured. Most panel systems are very cumbersome to use with automated equipment. Cross-rib configurations used in many panels are very difficult to put into proper position. Due to the complexity of this type of joining system, problems are created in the use of high speed automated assembly equipment, as disclosed in U.S. Pat. No. 2,055,399 to W. Dalton, issued Sep. 22, 1936, and U.S. Pat. No. 1,887,814 to J. Le Gall, issued Nov. 15, 1932.
Other panels have fastening systems such as nails, staples, scews, or tabs and slots. Fasteners and tabs may protrude through the outer surface of the skin, thus prohibiting the panel from having a desirable prefinished face. Currently, most prefabricated building panels require further covering to attain a finished wall. Coverings, such as wood siding, plywood, shingles, and stucco, are applied to the exterior of a building. Coverings are also applied to the interior, which include sheetrock, paneling, wall paper, wood, and plaster. These coverings, both interior and exterior normally are applied at the job site to complete the building.
Many systems use glue to secure the inner structure of their panel. Glue fastening systems usually have one flat surface placed against and glued to another flat surface. In this type of glue joint there may be a high rate of default, caused by improper amounts of glue being retained in the joint. With joints, as disclosed in U.S. Pat. No. 881,074 to J. Hoellig and M. Lidster, issued Mar. 3, 1908, it is almost impossible to get exactly the right amount of glue on the fastening areas.
After glue is applied, and upon the abutting of the structural members, any excess glue will be forced from the joint. When this excess glue is at the perimeter edge of the panel, it must be removed to permit other building components, such as panel joining members, to be used.
Some panels have slots through the skin, as disclosed in U.S. Pat. No. 4,894,974 to Mayhew, et al, issued Jan. 23, 1990. Due to the large cutouts, the slots placed at the corners of this panel may weaken the skin, allowing the corners to be damaged easily. The glue joint design in the Mayhew panel may create a number of defaults between the rib and the skin, and, additionally, requires that the outer perimeter edge be cleaned before any other building member can be applied.
Thus, previously known structural panels suffer from a number of disadvantages:
Many panels are limited in their structural abilities, with weakness resulting in damages to the panels during manufacturing, shipping, and assembly at the job site.
The use of urethane foam, verathane foam, or styrofoam as the core, or as insulation in building panels, creates an extreme fire hazard, and a very toxic situation if burning.
Many prefabricated types of building panels have fastening processes that render them unsuitable as a prefinished panel, in that they require additional interior and exterior coatings, after they are installed, to complete construction of a building.
Prefabricated building panels generally require a considerable amount of additional structural members and processes to complete a building.
Some internal rib design configurations create manufacturing problems. Such designs as tabs fitted through slots in the skins, and ribs fitting into tight grooves, make it very difficult to use high speed automated equipment in the manufacturing process.
The gluing process in some panels creates an additional step in the assembly process, where excess glue requires the cleaning of the outer perimeter edge of the panel, thus increasing the cost in manufacturing the panel.
Glue joints in internal rib structures are usually one flat surface joined to another flat surface with glue inserted between the two surfaces, thereby permitting a high degree of default in the gluing process.
Therefore, it is the overall object of this invention to provide a structural panel having a structural interlocking joint system which provides particularly high strength and resistance to deformation. Objects and advantages of the present invention are:
to provide a system that is well suited to a prefabricated building panel, as used in a modular wall system; PA1 to provide a prefinished building panel, suitable for either interior or exterior application; PA1 to provide a guiding system with grooves having angled edges that allow the use of high speed manufacturing equipment; PA1 to provide a rib-edge channel as a gluing means that greatly reduces the possibility of gluing defaults by retaining a measured amount of glue between ribs and grooves in the skin, thereby greatly increasing structural strength; PA1 to utilize the angle-edge grooves as a glue reservoir against overflow; PA1 to provide a non-hazardous building panel; PA1 to provide a extremely strong structural panel; and PA1 to provide a panel capable of using many different types of insulaton and acoustical products.